Research progress and technology of rare earth metal purification

Abstract:

Along with the development of rare earth materials, the preparation of novel rare earth function materials needed higher purity of rare earth metals. The methods for purifying rare earth metal mainly included vacuum melting, electrolytic refining, vacuum distillation/sublimation, fused-salt extraction, zone refining, solid-state electrotransport, electrochemical deoxidation, external getter method, plasma arc melting (Ar or Ar+H2), etc. The purification mechanism of rare earths metals was briefly explained, and the research progress and purification effects are summarized. Combining multiple means for removing impurities and promoting the level of equipment, in order to improve the effects of purification, and reduce the cost, shorten production cycle.